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HomeMy WebLinkAboutNCD980602163_19830901_Warren County PCB Landfill_SERB C_Recommended Anaytical Requirements for PCB Data Generated on Site During Non-Thermal PCB Destruction Tests-OCRSeptember 1, 1993 RECOMMENDED ANALYTICAL REQUIREMENTS FOR PCB DATA GENERATED ON SITE DURING NON-THERMAL PCB DESTRUCTION TESTS ANALYTICAL OBJECTIVES There are two major objectives for data on PCB concentration generated on site during non-thermal PCB destruction tests, or demonstrations, and during the general operation of a PCB disposal process: (1) to reliably quantitate the concentration of PCBs in the feed; and (2) to reliably identify and quantitate the concentraticn of PCBs in the product, waste, and effluent streams. OBSERVATIONS ON PREVIOUSLY DEMONSTRATED ANALYTICAL METHODS In most on-site PCB analyses associated with non-thermal PCB disposal processes that have been observed by EPA Headquarters, PCB concentrations have been determined with portable Gas Chromatographs equipped with Electron Capture Detectors (GC/EC). In our observations, sample preparation generally consists of (1) dilution of fluid containing (or formerly containing PCBs) or (2) stripping off a solvent that interferes with PCB analysis and redissolving the residue in a solvent (such as hexane or isooctane) that does not interfere with PCB analysis. In either case, the resulting fluid or extract is diluted to levels within the working range of the GC/EC. Internal standards or other measures are not commonly used to assure that the stated volume is, in fact, injected. There is common use of external standards and blanks. The GC/EC must be calibrated against a standard for quantitation. In the past. most, if not all, on-site analyses have relied on Aroclor™ mixtures of known concentration to calibrate the instrument. Many quantitation techniques employ a "total area· concept, or average the quantitation based on a few major peaks in an Aroclor™. These Aroclor™ mixture quantitation techniques are acceptable only if the analyte mixture closely resembles the standard. All analyses of original or untreated material is normally quantified based on an Aroclor™ standard. One rare exception might be that the original material has been partially dechlorinated (perhaps through an unsuccessful treatment by a PCB disposal process) and the original Aroclor™ formulation no longer exists. After treatment of the original PCB matrix, if the disposal process causes no changes in the chemical nature of the PCB molecules (e.g. distillation, solvent-soNent extractions, and solvent wash), then quantitation of the final treated PCB matrix is based on the appropriate Aroclor™. Analysis of PCB matrices treated by other disposal processes (e.g. chemical dechlorination, thermal processes, biol~ processes, photolytic degradation processes, electrolytic dechlorination, and catalytic dechlorination), which, during the process, chemically change the nature of PCB molecules and hence the character of any mixture of these compounds, must be quantified based on a congener standard, such as the DCMA (Dry Color PCB Disposal Section Analytical Requirements Revision 3, 09/01 /93 Page 2 of 4 Pages Manufacturer's Association) standard mixture of ten individual PCB compounds that is commercially available. In the GC/EC analysis of treated PCB material, where the original PCB formulation has been changed by the treatment process, all GC/EC peaks having retention times between and including the retention time· of the earliest eluting monochlorobiphenyl (MCB) (usually 2-chlorobiphenyl) and decachlorobiphenyl are considered to be PCBs. Only a more specific chemical analysis method, such as GC/Hall Electrolytic Conductivity Detector or GC/Mass Spectrometry, may be used to identify compounds in this GC/EC retention window that an analyst does not believe are PCBs. The most frequent problem observed at on-site laboratories is the difficulty in evaluating the concentration of the early eluting monochlorobiphen,yis (MCBs) and dichlorobiphenyls (DCBs). Most of the commonly found Aroclorsr do not have sizeable amounts of MCBs and DCBs present, and analysts have had some difficulty adjusting chromatographic conditions. In addition, quantitation using this type of GC/EC methodology is difficult (1) because of the large variability of response among the MCBs and DCBs and (2) because the level of 2 parts per million per resolvable GC/EC peak of a PCB compound in mineral oil dielectric fluid is close to the limit of quantitation for some of the MCB and DCB compounds. MINIMUM ANALYTICAL REQUIREMENTS Since the GC /EC analysis in the field is the final determination that the treatment is complete with many disposal processes, minimum analytical requirements have been established. The evaluation team auditing a demonstration will audit the on-site chemical analysis procedures. The audit will consist of the completion of an audit form and the observation of the analysis of a number of Quality Assurance samples prepared specifically for the audit. The following activities are necessary in preparation for an audit of PCB analytical procedures during a demonstration test: (1) A Quality Assurance (QA) plan must be prepared according to the guidelines set forth in ·interim Guidelines and Specifications for Preparing Quality Assurance Project Plans,· QAMS 0005/80, Office of Monitoring Systems and Quality Assurance (OMSQA), Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C. 20460, December 29, 1980. (OMSQA is now called the Office of Acid Deposition, Environmental Monitoring, and Quality Assurance.) (2) All chromatograms with raw data must be clearly and completely labelled with operating parameters, time, date, sample code, and other relevant information necessary to reproduce the analysis. , I PCB Disposal Section Analytical Requirements Revision 3, 09/01/93 Page 3 of 4 Pages (3) All results must be presented with units. The most common concentration units are ug/g for solids or liquids (except ug/L), and ug/m3 for air and stack gases. (4) Sample calculations must be provided. These calculations must show clearly how the raw data from the sampling process, sample preparation, and chromatograms, were converted to the final results reported. (5) Sufficient replicates, standard addition samples, blank samples, and other GC control samples must be analyzed and reported. The definition of ·sufficient' should be present in the QA plan required in #1 above. (6) Standard Operating Procedures (SOPs) must be documented and available for inspection if requested. (7) It must be demonstrated that monocholorinated biphenyls through decachlorinated biphenyls can be reliably quantitated in the range of concentration of the original untreated material and at the appropriate concentration range necessary to verify that the clean levels have been attained. There is no specifically required or designated analytical procedure. The requirements for a satisfactory analytical procedure are: (a) that the on-site analyses of audit samples for PCB concentration are performed satisfactorily; and (b) that the results of analyses of PCB concentration of split samples of feed waste and treated waste are confirmed by another laboratory performing adequately during audits by the PCB disposal section. GAS CHROMATOGRAPHIC ANALYSIS AND QUANTITATION OF TREATED OILS FOR SINGLE PCB CONGENERS In some cases, the chemical analysis of treated oils for PCBs in the implementation of 40 CFR 761 Regulations involves the identification and quantification of PCB congeners (there are 209 PCB congeners). In the past, most chemical analyses for PCBs measured concentrations by comparing the response of PCBs in treated oil to the fairly consistent amounts and distribution of congeners found in commercial mixtures added to the same matrix. This kind of comparison is perfectty acceptable when the treatment process, such as a physical separation process, does not change the chemical nature of the PCBs and therefore the nature of the PCBs or PCB mixture potentially remaining in the treated oil. However, following treatment by a destructive process or processes in which chemical reactions change the chemical nature of PCBs, the resultant, residual PCB congeners are changed in the amount and distribution from those present in commercial mixtures of PCBs. Analysis of oils treated by a destructive process or processes, where chemaca reactions change the chemical nature of PCBs, is best accomplished by procedures which can quantify individual PCB congeners. The most commonly used analytical method which provides acceptable quantitation of individual PCB congeners, without requiring extremely expensive equipment and chemical standards, compares gas PCB Disposal Section Analytical Requirements Revision 3, 09/01 /93 Page 4 of 4 Pages chromatographic peaks of treated oil samples to gas chromatographic peaks from ten selected PCB congeners (one from each level of chlorination.) Any analytical procedure proposed that provides acceptable results should include the following requirements: (1) Each gas chromatographic peak between the earliest eluting monochlorobiphenyl compound (usually 2-chlorobiphenyl) and decachlorobiphenyl is considered to be a single PCB congener. If an analyst believes that a gas chromatographic peak includes more that one PCB congener, resolution of the peak must be demonstrated (and the resolved peaks requantified) using another gas chromatographic column and/or using a different detector. (2) The level of chlorination of the PCB congeners represented by the gas chromatographic peaks is to be determined by comparison to the gas chromatographic peaks of a standard containing the earliest eluting monochlorobiphenyl (usually 2-chlorobiphenyl) and one representative from each level of chlorination of PCBs from dichlorobiphenyl to decachlorobiphenyl. Any standard meeting these designated specifications and prepared either commercially* or in a private laboratory may be used. The level of chlorination of a treated oil gas chromatographic peak is assumed to be the same as the chlorination level of the PCB congener of the nearest peak in this standard. If the retention time of a peak is exactly halfway between two standard peaks, the peak shall be assumed to represent a congener at the lower level of chlorination of the two nearby standard peaks. (3) Quantitation is based on comparison of the response of each peak in the treated oil with the response of the peaks in the PCB congener standard described in #2 above. The response of each treated oil PCB congener peak is assumed to be the same as the response of the nearest PCB congener in the standard. (4) In order for an oil treatment process to be considered successful, any resolvable gas chromatographic peak present and quantified by #1 through #3 above, must contain less than two parts per million (2 ppm). When using any chemical analysis methodology, proper Quality Control and Quality Assurance measures must be taken to assure that the Level of Quantitation of the method is below 2 ppm and that the instrumentation and all equipment are calibrated and within prespecified control criteria. In addition, since most gas chromatographic analyses of treated oils require dilution before chemical analysis, the analyst either (a) must take care to account for this dilution in calculations of original concentrations in the treated oil or (b) dilute the standard mixture in the same manner as a treated oil sample for a direct comparison of response. * There is a commercially available standard which meets these requirements. To,s standard was prepared originally for the Dry Color Manufacturers Association (DCMA) and is commonly referred to as the DCMA Standard. 'J ' " &EPA United States Environmental Protection Agency Research and Development Industrial Environmental Research Laboratory Research Triangle Park NC 27711 EPA-600/S2-82-069 July 1982 Project Summary Interim Guidelines for the Disposal/Destruction of PCBs and PCB Items by Non-Thermal Methods E. M. Sworzyn and D. G. Ackerman Thia report summarizes an interim resource and guideline document in- tended to aid USEPA regional offices in implementing the PCB Regulations (40 CFR 761) with regard to the use of non-thermal methods for the destruc- tion/ disposal of PCB1. The interim report describes and evaluates various alternative chemical, physical. and biological PCB removal and/or destruction technologies, in- cluding carbon adsorption, catalytic dehydrochlorination, chlorinolyais. sodium based dechlorination, photo- lytic and microwave plasma destruc- tion. catalyzed wet-air oxidation, and activated sludge. trickling filter, and special bacterial methods. Alternative destruction/diapoul technologies were evaluated using technical, regulatory, environmental Impact, economic, and energy require- manta criteria. Because the technol- ogies investigated are at various stages of development (only the sodium baaed dechlorination proceues are now com- mercially available). data deficiencies exist. and good engineering judgment was used to supplement available quantitative information. Of the technologies evaluated, many ■how the potential for greater than 90 percent PCB destruction with mini- mum environmental impacts end low to moderate economic co1t1. These technologies are catalytic dahydro- chlorination. sodium ba~d dechlorina- tion, microwave plasma, and photo- lytic proceues. · This Project Summ•ry was devel- oped by EPA 's lndustri•I Environmen- t•! Resurch Labor•tory. Ruearch Triangle P•rk. NC, to •nnounce key findings of the research project th•t is fully documented in • ssparate report of the same title (su Project Report ordsring information at b•ck). Introduction Polychlorinated biphenyls (PCBs) are derivatives of the compound bi phenyl in which 1 to 10 hydrogen atoms have been replaced with chlorine atoms. PCBs have extremely high chemical and ther- mal stability, making them quite useful in many commercial applications (e.g .. as dielectric fluids in capacitors and transformers; in heat transfer and hy- draulic systems. pigments. plasticizers, carbonless copying paper, and electro- magnets; and as components of cutling oils). Their wide use and the lack of recogni- tion of their hazards have led to their wide distribution in the environment (Fuller et al.. 1976). Although PCBs have fairly low acute toxicities, some adverse effects have been found in humans, laboratory animals. an((other organisms. There is some evidence that PCBs bioaccumulate and may be car- cinogenic (Fuller et al.. 1976). Concern over the PCB contamination problem led to a provision in the Toxic Substances Control Act (TSCA) that will require the eventual elimination of the use of PCBs in the U.S. The PCB Regu- lations, promulgated under TSCA (40 CFR 761 ). do not require removal of PCBs and PCB items from service earlier than· would otherwise be required; but when PCBs and PCB items are removed from service, disposal must be in ac- cordance with the PCB Regulations. Other acts which govern the disposal of PCBs include: the Resource Conserva- tion and Recovery Act, the Clean Water Act. the Clean Air Act, the Occupational Health and Safety Act. and the Marine Protection. Research, and Sanctuaries Act. Because there is a large amount of PCB in existence that will need disposal, the Electric Power Research Institute projected a shortfall of utility waste PCB disposal capacity (landfill and inciner- ator) 1n most EPA regions after January 1, 1980 (EPRI, 1979). In addition, there will be a smaller quantity of waste PCBs from commercial and industrial uses which will require disposal. The PCB Regulations provide for four general disposal methods: • Annex I incinerators for PCBs and PCB items having greater than 500 ppm PCB content. • High etticiency boilers for PCB- contaminated liquids having PCB contents 50 ppm or greater but not greater than 500 ppm. • Annex II chemical waste landfills for PCB-contaminated liquids (equal to or greater than 50 ppm but not greater than 500 ppm); non-liQuid PCBs in the form of contaminated soils. rags. or other debris; and all dredged materials and municipal sewage sludges that contain PCBs. • Other approved method for PCBs and PCB items that are subject to incineration. The full report is an interim guidelines document applying solely to the dis- posal/destruction of PCBs by methods other than incineration in Annex I incinerators or high efficiency boilers. Annex II chemical waste landfills, or as municipal solid waste. Ev~lustior. Criteria for i'liu,1-ThtHmal PCB Destruction Processes Since the EPA considers non-thermal PCB destruction processes as alter native 2 methods to incineration, the basis for evaluation of an alternative (non- thermal) system is its performance relative to a thermal system. As stated in the PCB Regulations. 40 CFR 761.10(e). an alternative system must be demonstrated to "achieve a level of performance equivalent to Annex I incinerators or high etticiency boilers." Before approving any non-thermal de- struction process. the Regional Admin- istrator must be able to determine that the alternative system provides "PCB destruction equivalent to" the appropri- ate thermal method and "will not pre- sent an unreasonable risk of injury to health or the environment." Chapter 2 of the full report describes the development of an evaluation meth- odology which is not process specific. It involved taking characteristics of any given non-thermal process and compar- ing them with criteria related to the regulatory, technical, environmental, economic, and energy performance characteristics of thermal processes. Technical factors which should be included in an evaluation of a non- thermal process are: destruction etti- ciency, range of PCB concentrations in the waste. ability of the process to handle wastes of varying PCB content. physical form of PCBs the process can handle, restrictions on non-PCB waste constituents, special process require- ments. state of the technology, overall facility design and operation, and re- source reclamation. Environmental factors which should be included in the overall evaluation are: environmental impacts of the disposal operation itself, environmental impacts of disposal of process wastes, potential impact of accidents and transportation of PCBs to the disposal site, ettluent monitoring programs, and closure and post-closure plans. Economic factors considered in the overall evaluation are: capital costs or the cost of facility construction or modification, operating costs. disposal costs, credits for products or by-products, financial requirements related to closure and post-closure monitoring and main- tenance, and regulatory costs. Energy factors that should be included in the evaluation are: debits, credits, and re- source recovery. Most of the above regulatory, techni- cal, environmental, economic. and energy factors are discussed for num- erous alternative disposal methods in the full report. Non-Thermal Destruction Methods The non-thermal destruction pro- cesses described in this report are grouped into two broad categories: physicochemical methods and biological methods. Physicochemical methods ex- ploit chemical or physical characteristics of PCB molecules to achieve destruction or detoxification. Biological methods all employ microorganisms which metabo- lize PCB molecules to less chlorinated , PCBs or non-chlorinated compounds. None of the alternative methods de- scribed here or in the full report are at commercial scale, so that only limited data ar13 available. There are, therefore, substantial technical. environmental, economic, and energy information gaps. Some of the methods have not been applied to PCB degradation but otter interesting possibilities. Other methods have been applied to PCBs only in dilute aqueous solution, but are covered be • cause of potential adaptability to PCBs in dilute organic solution (e.g .. mineral oil dielectric fluid). Comparison of these alternative methods with thermal methods is necessary, but many of the comparisons are necessarily qualitative. Destruction etticiencies. for methods that have been so tested. are well below the performance requirements of Annex I incinerators or high efficiency boilers. Currently, none of the alternative meth- ods meet the destruction efficiency requirements of the PCB Regulations. However, destruction efficiency is only one factor that must be considered in the approval process. Table 1 presents a comparison of technical, environmental, economic, and energy factors associated with thermal (Annex I incinerators and high efficiency boilers) and non-thermal destruction/disposal methods. Adsorption Processes Adsorption processes are useful for removing chlorinated hydrocarbons from an aqueous waste stream by contacting it with activated carbon by passing it through a vessel filled with a carbon slurry or granules. Impurities from the aqueous stream are removed by adsorption onto the carbon. Activated carbon has an attinity for organics. and its use for organic contaminant removal from wastewater is common. In 1976, General Electric's Capacitor Products Department installed a system to eliminate the discharge of PCBs to the .. Table 1. Comparison of Thermal and Non-Thermal Disposal/Destruction Methods Potential for Destruction or Large Scale Conversion Method Application Annex I Incineration High High Efficiency Boilers High Activated Carbon Absorption Processes High Catalytic Dehydrochlori- nation Medium Chlorinolysis Low Goodyear Process High Microwave Plasma Medium Uzonauon Processes Medium Photolytic Processes Low Sodium-Oxygen-Polyethyl-Medium ene Glycol Sunohio Process High Catalyzed Wet Air Oxidation Medium Activated Sludge Low Trickling Filter Low Special Bacteria, Methods Low 1 Method is currently used commercially. 2 Proven research method only. 3 Limited or no data base. Current Status of Technology as Applied to Destruction PCB Processing Efficiency , >99.99% 1 >99.99% 3 Not applicable 2 99+% 3 Low 3 92% 2 95% 3 Not applicable 2 90-95% 2 95% 3 99+% 2 99+% 3 Not applicable 3 Not applicable 3 Not applicable 4 Potential controllable method with minimum environmental impact. 5 Potential solid residue or wastewater disposal problem. 6 Low capital investment and moderate operating costs. 7 Moderate capital investment and operating costs. 8 Large capital investment and operating costs. 9 Resource recovery option. 10 Requires recycling or disposal of adsorption medium. 11 Potential residual toxicity of by-products. 12 Potential return on investment. s Solid a Aqueous g Gas • .1 Li~!::"d Feedstock g.l.s I • l.g I 1 l.g II I I I 11.l.s II 8 II Hudson River from its Hudson Falls and Fort Edward manufacturing plants. This adsorption process worked extremely well for dilute aqueous streams contami- nated with PCBs (Arisman. 1979). but was not very cost effective. High cost and carbon disposal or regeneration requirements caused EPA and GE to ---------·-· ..... ____ ... _ PCB Overall Overall Range. Environmental Economic ppm Impact Impact .>50 4,5 8 <50 4.5 8 Dilute amounts 4.5.10 7.9 <50 5. 11 7.9 Not 4.5 8.9.12 applicable <500 4 6.9 50-500 4.5 7 Dilute 5. 11 8 amounts <50 5.11 7 50-500 11 7.9.12 and>500 50-500 4 6,9.12 and>500 50-500 3 7 and>500 Dilute 11 7 amounts Dilute 11 7 amounts Dilute 11 7 amounts investigate alternate treatment systems; i.e .. UV-Ozonation and catalytic reduc- tion. Application of activated carbon ad- sorption processes is less common to non-aqueous streams. A study (U.S. Air Force. 1976) on using activated carbon to remove the 2.3.7.8-tetrachlorodi- benzo-p-dioxin (TCDD) contaminant from Herbicide Orange concluded that. though the process was technically and economically feasible. the technology to dispose of the TCDD contaminated charcoal did not exist. Therefore. Herbi- cide Orange stocks were successfully incinerated at sea (Ackerman et al., 1978). From a technical point of view, adsorp- tion processes for removing organic compounds from liquid streams are 3 • attractive because they offer the possi- bility of resource recovery; e.g., removal of PCBs from miner al oil dielectric fluids with possible reuse of the mineral oil. However, to be economical, the PCBs must be removed from the adsorbent, so that an adsorption process applied to PCB disposal must be coupled with a second disposal/destruction process to handle PCBs removed from the absorb- ent during regeneration of the activated carbon. Catalytic Oehydrochlorination Catalytic dehydrochlorination is based on the reaction of polychlorinated hydro- carbons with hydrogen gas under high pressure in the presence of a catalyst (LaPierre et al., 1977). The reasoning behind this reaction is that partially dPchlorinatP.d or nonchlorinated com- pounds could be less toxic and. there- fore, could be biodegraded more easily than highly chlorinated compounds. This process has been applied directly to the detoxification of PCBs, but only on the laoorato,y scale. A study at the Worcester Poly- technic Institute indicates a complete conversion of PCBs into dechlorinated biphenyls (LaPierre et al., 1977). Catalytic dehydrochlorination should be able to handle a wide range of PCB contaminated material, if they are in the liquid state. Transformers with a PCB concentration of> 500 ppm, as well as PCB capacitors and mineral oil dielectric fluids with PCB contents of 50-500 ppm, should be amenable to treatment by this process. PntPt'ltial impacts of the disposal operation, as well as the disposal of process wastes, should be low. Accord- ing to current studies. a properly de- signed process should not produce toxic off-gases or contaminated aqueous residues. lack of economic data prohibits a cost assessment of a dehydrochlorination conversion facility. Hydrocarbons pro- duced by this process could be used or sold as fuel oil. This economic credit could lower the cost of PCB processing substantially. Qualitatively, capital in- vestment and operating costs appear to ~-= :-:iod::::::z. Chlorinolysis Chlorinolysis is an established tech- nology for converting chlorinated hydro- carbons to carbon tetrachloride. This is a vapor-phase reaction in which chlorine is added to the waste material under high pressure and low temperature (or high temperature and low pressure). A catalyst is not used in this process (S.S.M .. 1974). If the waste consists of only carbon and chlorine atoms, the product will be carbon tetrachloride. If the waste contains oxygen or hydrogen, carbonyl chloride and hydrogen chloride are also produced (S.S.M ., 1974). Chlorination as a method of disposing of hazardous wastes was first suggested in 1974. Farbwerke Hoeschst Ag, Frank- furt/Main. Germany, has developed a process in which hydrocarbons and their chlorinated derivatives are completely converted to carbon tetrachloride and hydrogen chloride at pressures up to 24 MPa and temperatures up to 893 K (Krekeler et al .. 1975). Chlorinolysis has not been applied directly to PCB disposal, but a variation of the process may be adaptable. Al- though the Hoeschst chlorinolysis pro- cess can handle chlorinated benzene derivatives on a limited scale only, it may be worthy of evaluation. The feed must be a liquid, and most impurities must be removed before processing. Chlorinolysis works best on aliphatic compounds. The destruction efficiency for PCBs should be extremely low in the existing process since aromatic compounds are not processed efficiently. The process works poorly for an aromatic content of greater than 5 percent calculated as benzene. Potential environmental impacts when considering the construction and operation of a chlorinolysis plant include shipment and handling of the hazardous organochlorine wastes prior to chlorin- olysis, control of the potential gas and liquid effluents after conversion. and handling and storage of the final prod- ucts. Emissions from manufacturing, storage, and transport of polychlorinated aromatics (particularly PCBs) are pos- sible. Accidental spills and leaks of both solid and liquid wastes are the primary sources of emissions. Conventional spill and leak prevention procedures should make the process operationally safe. The Goodyear Process The Goodyear Tire and Rubber Com- pany recently developed a process to degrade microquantities (e .g .. 120 ppm) of PCBs (Goodyear, 1980). This process involves preparing sodium naphthalide and contacting this reagent with the PCB-containing liquid. The reagent ab- stracts chlorines from the PCB molecule, and NaCl and non-halogenated poly- phenyls are formed. The reaction i rapid at room temperature. The Goodyear process appears we developed on the laboratory scale. Th available literature source indicates on that the Goodyear process is technical applicable at this time to handle mixturt of Aroclors (a Monsanto trademark) ; 50-500 ppm concentrations. Undestroyed PCBs remain in H processed heat transfer fluid. This flu could be recycled or reused directly, ! that there is no real environment impact expected from this process effl ent. Overall, the potential environment impacts of the disposal operation appe to be low although a thorough asses ment cannot be made without more tE data. Generally, the Goodyear process a pears to be relatively low in cost a may be adaptable to both small a large scale operation. A detailed ec nomic evaluation is needed before ti process may be judged economicc justifiable. With large scale applicati, product recovery of purified mineral may reduce costs significantly. Microwave Plasma Methods Lockheed's Palo Alto Research Lat atory (LPARL) has developed a proc to· destroy PCBs and other hazard, materials by microwave plasma trf ment (Oberacker and Lees. 1 977). search started on the bench scale , has been expanded to a unit which , successfully destroy PCBs at the rat 0 .45-2.3 kg /hr. A future goal is develop a 40-50 kg /hr version. A 1 5 kW microwave plasma reac) system capable of destroying 2-11 kg of organic wastes, including PCB~ now in operation. Laboratory sc experiments have determined that destruction efficiencies of Aroclor 1 and 1254 are 99 percent using 4.6 4.5 kW microwave power. respecti, The process should be able to des PCB concentrations of 50-500 i effectively. Further research is neE to determine the maximum concer tion of PCBs that can be destroyed , a high destruction efficiency. Although microwave plasma dest tion of PCBs is a controllable me which yields innocuous products, i as CO2 and H2O, potentially hazar, products such as CO and organoc ines will also be produced. An environmental assessment o microwave plasma disposal oper. must consider the shipment and h .. • , ling of the PCB material prior to process- ing, control of the potential gas and liquid effluents after conversion, and the handling. storage. and disposal of final products. Extremely high tempera- tures 11nd pressures occur throughout the system. Special safety techniques would have to be used to guard against the accidental release of hot, corrosive. or toxic vapors. The use of a caustic scrubber should keep emissions fairly low. Since the effluent streams from a scrubber are mainly liquid, any particu- lates emitted would be dissolved in the liquid effluent as suspended particles. Very little information exists on the economics of a microwave plasma pro- cess adapted to PCB destruction. Over- all, capital costs for a microwave plasma processing facility may be high since useful by-products may not be recover- able. Electrical costs should decrease as microwave power technology advances. Future improvements in basic plasma design should reduce operating costs. Currently, it appears that a large-scale microwave plasma destruction unit will entail moderate capital investment and operating costs. Ultraviolet-Ozonolysis Ultraviolet (UV)-ozonolysis is a process that destroys or detoxifies hazardous chemicals in aqueous solution utilizing a combination of ozone and UV irradi- ation. Fairly simple equipment is re- quired on the laboratory scale: a reaction vessel. an ozone generator. a gas dif- fuser or Sparger, a mixer, and a high pressure mercury vapor lamp (Wilkinson et al., 1978). UV-ozonolysis has proved to be effective in destroying dilute quantities of PCBs in industrial waste water effluents. Experimentation has been on the laboratory level only. Scale- up to pilot plant capacity has not been attempted. UV-ozonolysis of dilute aqueous streams contaminated at various PCB levels was performed by General Elec- tric's Capacitor Products Department at its Hudson Falls and Fort Edward manu- facturing plants (Arisman, 1979). De- struction efficiencies for most experi- ments were 93 ± 3 percent. PCB concentrations ranged from 30 to 100 ppb in aqueous solution. The possibility of the formation of reaction products, harmful to aquatic life, must be considered. Residual amounts of halogenated compounds, as well as trace metals, may be contained in the waste effluents. An assessment of the types of final products that will be produced is necessary. Any auxiliary disposal operations such as adsorption. filtration, or incineration must also be analyzed for possible environmental impact. Major capital equipment costs will be the reactor, ozone generator and power supply, and the UV irradiation source and power supply. Major operating costs include electrical energy and labor. In general, UV-ozonolysis should be cost competitive with traditional waste water processing facilities. Photolytic Methods Photolytic processes are based on the principle that UV radiation activated molecules which may then under- go chemical reaction. Much research has been done on the photodecomposi- tion of various classes of pesticides by using UV radiation (Crosby and Li, 1969; Plimmer. 1970, 1972, 1978; Rosen, 1971; and Mitchell, 1961 ). The photode- composition of PCBs is now being studied in the laboratory to determine products formed and the effects of solvents on product formation and rates of reaction (Ruzo et al.. 1974). Currently, very little is known about the photochemical properties of the many PCB isomers. A few studies have shown that the primary reaction at wavelengths > 290 nm is stepwise dechlorination. The actual dechlorir.ation products have rarely been identified (Ruzo et al.. 1974). In 1974. a study was carried out to determine the reaction products of PCB photodecomposition in different sol- vents (Ruzo et al.. 1974). It was con- cluded that if photolysis is to occur. the PCB molecule must absorb light energy above 290 nm or receive energy from another molecule through an ·energy transfer process. The product may be a complex mixture in which isomerization. substitution. oxidation. or reduction processes have occurred. To date, there have not been any studies of photolysis of PCB-contaminated mineral oils or hydraulic fluids. Destruction efficiencies as such have not been determined in these laboratory studies. A 90-95 percent yield of de- chlorinated PCB in methanol solution has been determined (Ruzo et al., 1974). Methanol substitution products were also found in these experiments. The photolysis process may be appli- cable over a wide range of PCB concen- trations. The important factor determin- ing the concentration range of the PCBs is its solubility in the solvent. Research has not been done on an actual PCB- contaminated mineral oil. so that the applicability of this process to PCB disposal/destruction has not been com- pletely validated. The precise chemical nature of the process wastes needs to be investigated before assumptions about process waste disposal impacts on the environment can be made. Certain chlorinated com- pounds may exist in the waste streams that could be harmful to the environ- ment. Vapor effluents could contain HCI and photoactive compounds. Aqueous effluents could contain chlorine and components that did not react with the UV radiation. Factors that will affect overall capital and operating costs for a large scale photolysis processing plant include land availability and cost. types of chemicals and reagents required, labor. monitor- ing. and application costs. Based on the limited information available, scaled up operating and capital costs appear to be moderate. Possible economic credits could accrue if some of the products are saleable or reusable . Chemical Degradation with Sodium-Oxygen-Polyethylene Glycol Reaction of PCBs with sodium- oxygen-polyethylene glycols is based on the fact that sodium metal finely dis- persed in certain solvents can serve as a chemical reactant. The reactivity is dictated by the mechanism of decompo- sition of the PCB molecule laboratory experiments have shown that the react- ing solution should be composed of polyethylene glycol (avg M .W. = 400. dried over anhydrous Na2SO.) and metallic sodium. PCB oil is added to this solution to produce polyhydroxylated bi- phenyls and hydroxy-benzenes (Pytlewski et al.. 1980). This technology exists on the laboratory scale only. laboratory studies have indicated an approximate 95 percent conversion of the PCB oil. Precise destruction effici- encies have not been determined. The process appears to be applicable over a wide range of PCB concentrations. particularly in the 50-500 ppm range. large amounts of H2 gas and NaCl will be evolved in this process. The H2 gas should be drawn off and collected as a source of energy. NaCl disposal should not create any special disposal problems. The recovered H2 gas could be used as an additional source of energy to melt 5 the NaCl. The evolution of large amounts of Hz gas means that the use of open flames. electrical sparking. and electric heating elements must be avoided. The reaction with the sodium metal should be started with heat supplied by steam. Franklin Research Center engineers made a preliminary cost evaluation for the commercial destruction of PCBs by this process. They determined decompo- sition cost of almost 70C/kg of PCBs (Pytlewski et al., 1980). Recovery credits for Hz gas and the polyhydroxylated biph·enyls could bring the cost of the operation low enough to make the process profitable. The Sunohio Process Sunohio has developed a process to break down the PCB molecule into its two primary components. biphenyl and chlorine. The chlorines are converted to chlorides, while the biphenyl molecule is converted to polymeric solids. The process is called PCBX. a Sunohio trade- mark. Full scale stationary and mobile units are now complete. The unit is designed to: (1) heat transfer mer oil and filter it. removing moisture. acids, and other contaminants; (2) remove and destroy -PCBs contained in the trans- former oil but not the oil itself, and (3) destroy pure PCBs. The equipment, contained in a large tractor/trailer, is self-contained and either can generate its own power or may be hooked up to an external electric power source. Trans- former oils can be removed from fully charged transformers and, after treat- ment. can be returned to the same tra~sformer in minutes. The original goal in process develop- ment was to remove all PCBs from the treated fluids. Experimental fluids used for laboratory studies have contained as little as 100 ppm and as high as 10.000 ppm PCBs. These fluids after treatment are claimed to have contained Oto 40 ppm PCBs. respectively. The process appears to be able to handle a wide range of PCB concentrations and types of fluids. An environmental impact study has not been C\lrried out for the PCBX process. Each generic effluent stream should be andlyzed for composition and percent solids. Overall, the potential environmental impact of the disposal operation appears to be very low. Sun- ohio claims that either very little or no toxic products will be produced. A cost analysis of the PCBX process is not available. It appears that a major 6 capital investment is not required since the system is completely portable. It is claimed that transformer oil can be decontaminated for about S264-S792 per m3• The theoretical reagent cost is about $1 .10 per kg (Sunohio, 1980). Cost credits may be earned by reusing the decontaminated heat transfer oil instead of discarding it. Catalytic Wet Air Oxidation Wet air oxidation is based on the principle that a solution of any organic material can be oxidized by air or oxygen if enough heat and pressure are applied. At temperatures of 433-613 K and pressures of 3.1-17.2 MPa, sewage sludges will be oxidized to alcohols, aldehydes. and acids. At higher tempera- tures and pressures. the organic mate- rial can be oxidized to CO2 and Hz (Astro, 1977). IT Enviroscience (ITE), Inc., recently developed a catalyzed wet air oxidation process for the destruction of PCBs. This process is patented and involves the direct oxidation of PCBs by air or oxygen in an acidic aqueous medium at high temperatures. This process can be used for organic material in aqueous solution, organic liquid residues. and specific types of sludges and solid residues. Special attention was given to PCBs in the development of this process (IT Enviroscience, 1980). This catalyzed wet air oxidation process utilizes a water soluble, single-phase catalyst system. It differs from other processes in that the catalyst is homogeneous. and, unlike uncatalyzed wet air oxidation. heat and pressure requirements are lower. The catalyst itself is used to promote the necessary oxygen transfer. This technology is new and not.com- pletely researched. ITE recently com- pleted feasibility testing and process development studies for the destruction of PCBs. Over 50 tests were made on PCBs by ITE in a 1 liter titanium stirred reactor to define process conditions in the laboratory. Greater than 90 percent of PCBs were repeatedly destroyed by oxidation at 523 K for 2 hours. It is important to note that it is not necessary to achieve 99+ percent destruction of the PCBs since unreacted PCBs will remain in the reactor until destroyed. (This retention of undestroyed PCBs reduces throughput.) The laboratory studies used 5-6 g of Askarel (56 percent PCBs and 44 percent trichlorobenzene) to determine destruction efficiencies. This process may be adaptable over a wide range of PCB concentrations. Transformer oils with> 500 ppm PCBs might possibly be treated by this process. It is extremely difficult to estimate environmental impacts at this time. It appears that minimal environmental damage would be expected from this PCB disposal operation since the PCBs remain in the reactor until destroyed and since there is no aqueous bottoms product. CO2, N2, H20 vapor, volatile organics. and inorganic solids leave the reactor. The water and condensable organics are retained in the reactor for complete degradation. This step reduces the volume of toxic organic substances that could be contained in the effluent streams. The vent gases are low in volume and could be treated by conven- tional techniques. Further research is required to develop a detailed environ- mental assessment of this process. Economic data for the ITE method are not available. Required information in- cludes: (1) capital costs. (2) operating costs. (3) disposal costs. (4) credits for products or by-products. and (5) regula- tory costs. A cost analysis and feasibility study is currently being carried out by ITE to determine the economic viability of this process. Qualitatively, this pro- cess seems to be economically feasible if adequate throughput can be attained. Little or no added energy is required. and no auxiliary fuel is consumed Chemical consumption is low. lowering the cost appreciably. Biological Methods Biological disposal methods are all based on the ability of microorganisms to degrade toxic organic compounds, such as PCBs. The major differences between the various methods lie in the means of supporting and contacting the micro- organisms with the fluid containing the species to be degraded. means of provid- ing oxygen to the microorganisms. and in pre-and post-treatment. The literature review indicated that most commercial applications of biolog- ical processes are to aqueous streams containing relatively small amounts of organic compounds. Laboratory studies show that pure Aroclor mixtures are degraded and that degradation rates are inversely related to increasing chlorine substitution. Studies (U .S. Air Force. 1976) show that microorganisms could degrade concentrated Herbicide Orange components over a period of years. Commercial land farming is used to degrade oil-contaminated industrial aqueous wastes. However, PCBs ere more refractory than the major Herbicide Orange components and oils. Two bio- logical processes that may be of some interest are activated sludge and trick- ling filter methods. Both processes are currently used for wastewater treat- ment. Activated Sludge Treatment Activated sludge treatment is classi- fied as an aerobic process because the microbial solution is suspended in e liquid medium containing d issolved oxygen. Complete aerobic treatment without sedimentation is carried out as the wastewater is continuously fed into an aerated tank where microorganisms digest and flocculate the organic waste. The microorganisms (activated sludge) settle from the aerated liquor in a final c1ari11er ano are returned to the aeration tank. The effluent emerges from the final settling tank purified. Tucker, l itschgi, and Mees (1975) did laboratory testing with a continuous feed activated sludge unit. With a feed rate of 1 mg/ 48 hrs, they reported an 81 percent degradation of Aroclor 1221 , 33 percent degradation of Aroclor 1016, 26 percent degradation of Aroclor 1 242, and 15 percent degradation of Aroclor 1254. Trickling Filter Methods Trickling filters consist of crushed rock. slag. or stone. These materials provide a surface for biological growth and passages for liquid and air. The pr imary treated waste flows over the microbial surface. The soluble organic material is metabolized, and the insol- uble material is adsorbed onto the media surface (Wilkinson et al., 1978). The biological components are bacteria, fungi, and protozoa. The bottom portions of the filter contain nitrogen fixing bacteria. Trickling filters are classified as low (standard), intermediate, high, or super rate filters based on hydraulic and organic loading rates. Since an aqueous medium is necessary, only dilute dis- solvable PCB isomers may readily be contacted with the act ive microbes. Neither of the l'lb'>ve biological meth- orlc: .-~n tu:> C""1~;1e·P.d technically appli- cable to general disposal of PCBs and PCB items. While trace quantities of PCBs could be fed into a commercial scale process and while some degrada- tion would occur, destruction would not be complete, and the amounts fed would be so small as not to aid aooreciably the PCB disposal problem. Further research is warranted, but the research might most profitably be pursued in the follow- ing areas: (1) more effective treatment of sewage and wastewater already con- taminated by PCBs, (2) treatment of PCB-contaminated dredge spoil, and (3) developing microorganisms effective et degrading PCBs. Because destruction efficiencies of current processes de- crease rapidly with increasing chlorine substitution, it is doubtful whether any activated sludge or trickling filter process will be capable of destruction effici- encies equivalent to those of high efficiency boilers or Annex I incinerators. References Ackerman, 0 . G., et el. 1978. At-See Incineration of Herbicide Orange Onboard the MI T Vulcanus. EPA- 600/2-78-086 (NTIS PB 281 690). Arisman. R. K., 1979. Demonstration of Waste Treatment Processes for the Destruction of PCBs and PCB Sub- stitutes in an Industrial Effluent. Draft Report. EPA Grant S804901. General Electric Company. Astro Metallurgical Corp. 1977. Astrol™ Wet Oxidation Waste Treatment Systems. Bulletins No. WT-77-1 end WT-77-3. Crosby, 0 . G. and M. Y. Li. 1969. Herbicide Photodecomposition. In Degradation of Herbicides. P. C. Kearney and 0 . 0 . Kaufman, eds. Marcel Dekker, Inc., New York, NY. EPRI. 1979. Disposal of Polychlorinated Biphenyls (PCBs) and PCB-Contam- inated Materials. Volume I. Electric Power Research Institute. Report FP-1207, Volume 1. Fuller. B., J. Gordon, and M. Kornreich. 1976. Environmental Assessment of PCBs in the Atmosphere. M itre Corp. Technical Report MTR-7210, Rev. 1. Goodyear Tire and Rubber Co. 1980. A Safe, Efficient Chemical Disposal Method for Polychlorinated Bi- phenyls. IT Enviroscience. 1980. Catalyzed Wet Oxidation Process for Destruction of PCBs Process, Description and Summary of State-of-the-Art. IT Enviroscience, Inc., Knoxville, TN. Krekeler, H., H. Schmitz, and 0 . Reblan. The High-Pressure Chlorolysis of Hydrocarbons to Carbon Tetrachlo- ride. Paper presented et the National Conference on the Man- agement and Disposal of Residues for the Treatment of Industrial Wastewaters, Washington, DC. February 1975. laPierreJ R. B., E. Biron, D. Wu. l. Guczi, and W . l. Kranich. 1977. Catalytic Hydrodechlorination of Polychlori- nated Pesticides and Related Sub- stances. Worcester Polytechnic Inst. Prepared for EPA"s Municipal Environmental Research labora- tory. EPA-60018-77-013 (NTIS PB 262 804). Mitchell, l. C. 1961 . The Effect of Ultra- violet light on 141 Pesticide Chem- icals. J. Assoc. Off. Agr. Chem. 44, 643. Oberacker, D. A., and S. lees. 1977. Microwave Plasma Detoxification of Hazardous and Toxic Materials: News of Environmental Research in Cincinnati. USEPA Cincinnati, OH. Plimmer. J. R. 1970. The Photochemistry of Halogenated Herbicides. Res idue Rev. 33:47-74. Plimmer. J. R. 1972. Pr inciples of Photo- decomposition of Pesticides. Degra- dation of Synthetic Organic Mole- cu I es in the Biosphere, San Francisco. Published by National Academy of Sciences, Washington, DC. Plimmer. J. R. 1978. Approaches to Decontamination or Disposal of Pesticides: Photodecomposition. 174th National Meeting. American Chemical Society, Chicago. IL. Pytlewski, l. l., K. Krevitz, A. B. Smith. E. J . Thorne, and F. J. laconianni. 1980. The Reaction of PCBs with Sodium, Oxygen, and Polyethylene Glycols. In Treatment of Hazardous Wastes: Proceedings of the 6th Annual Research Symposium. Chicago, IL. EPA-600/9-80-011 (NTIS PB 80-175 094). Rosen, J. 0 . 1971 . Photodecomposition of Organic Pesticides. In Organic Compounds in Aquatic Environ-. ments. S. J . Faust and J . V. Hunter, eds. Marcel Dekker Inc., New York, NY. Ruzo. l. 0 ., M. J . Zabik, and R. D. Schoetz. 1974. Photochemistry of Bioactive Compounds: Photoprod- ucts and Kinetics of Polychlorinated Biphenyls. J . Agr. Food Chem. (22)2. S.S.M . Emerging Technology of Chlori- nolysis. 1974. Environmental Sci- ence and Technology. 8(1 ): 18-19. Sunohio Corp. 1980. Sunohio's PCBX Process. Canton, OH . 7 Tucker, E. S .. ·w. J. litshgi, and V. M. Mees. 1975. Migration of Polychlori- nated Biphenyls in Soil Induced by Percolating Water. Bulletin of Envi- ronmental Contamination and Toxi- cology, 13:86-93. U.S. Air Force. 1976. Environmental Impact Analysis Process. Amend- ment to the Final Envi.ronmental Statement on the Disposition of Orange Herbicide by Incineration. Wilkinson, R. R .. G. L. Kelson, and F. C. Hopkins. 1978. State-of-the-Art Report: Pesticide Disposal Re- search. EPA-600/2-78-183 (NTIS PB 284 716). E. M. Sworzyn and D. G. Ackerman are with TRW, Inc., Environmental Division, Redondo Beach, CA 90278. David C. Sanchez is the EPA Project Officer (see below). The complete report. entitled "Interim Guidelines for the Disposal/ Destruction of PCBs and PCB Items by Non-thermal Methods,• (Order No. PB 82-217 498: Cost: $ 16.50, subject to change/ will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Industrial Environmental Research Laboratory U.S. Environmental Protection Agency ~ Research Triangle Park, NC 27711 sf/-~~ Un,ted States Emmonmenta! 1'· :>tl·"t1on Agency Center for Emmonmenral Research lnformat,on Postage and Fees Pa,d Environmental Protection Agency Cinc,nnat, OH 45268 EPA 335 C)ff ,c,al Bus,ness Penalty for Private Use S300 • • /